OpenCv2.4.4中实现图像旋转和缩放

#include<iostream> #include<opencv2/imgproc/imgproc.hpp> #include<opencv2/highgui/highgui.hpp> using namespace std; using namespace cv; #define SCALE 1.3 //缩放比例 int main() { Mat src = imread("pic3.png"); Mat dst;//输出图像 int angle = 30;//旋转角度(正值表示逆时针旋转) //为了保证无论如何旋转都能放下，输出图像的长和宽都设为输入图像对角线长度乘以SCALE int length = sqrt(src.cols*src.cols + src.rows*src.rows) * SCALE; //建立临时图像，长宽都是源图像的对角线长度，将源图像复制到临时图像的中心后再变换 Mat tempImg(length,length,src.type());//临时图像，大小和输出图像一样大 int ROI_x = length/2 - src.cols/2;//ROI矩形左上角的x坐标 int ROI_y = length/2 - src.rows/2;//ROI矩形左上角的y坐标 Rect ROIRect(ROI_x,ROI_y,src.cols,src.rows);//ROI矩形 Mat tempImgROI2(tempImg,ROIRect);//tempImg的中间部分 src.copyTo(tempImgROI2);//将原图复制到tempImg的中心 Point2f center(length/2,length/2);//旋转中心 Mat M = getRotationMatrix2D(center,angle,SCALE);//计算旋转的仿射变换矩阵 //输出看看算出的矩阵是什么 cout<<"变换矩阵："<<endl; cout<<M.at<double>(0,0)<<","<<M.at<double>(0,1)<<","<<M.at<double>(0,2)<<","<<endl; cout<<M.at<double>(1,0)<<","<<M.at<double>(1,1)<<","<<M.at<double>(1,2)<<","<<endl; warpAffine(tempImg,dst,M,Size(length,length));//仿射变换 //显示 imshow("src",src); imshow("tempImg",tempImg); imshow("dst",dst); waitKey(0); return 0; }